Interesting discussion here of "pulsing foot."
https://forum.officiating.com/...er-pulsing-foot.html
To re-state my question:
HS baseball
Runner at first
RHP suspects that r1 may be stealing on this pitch (he's right!)
RHP comes completely set; his hands are still
He does a long hold, with hands remaining still, then he lifts front foot 1-1.5" off the ground and places it back down in the same place.
Then, about one second later, he wheels and picks to first.
R1 got caught leaning is tagged out diving back to the bag.
As described (specifically "completely set" -- it's more than just the hands), that's a balk. All codes.
Now that I've had a chance to watch the GIF, I can say that the GIF is NOT a balk. The GIF and the explanation above do not match.
Also, it's very hard to learn about balks by watching MLB. Even if the rules are the same (and FED does have some differences), there are lots of judgment words in the rules and the way it gets interpreted is different. As a general statement (with many exceptions, I admit), MLB pitchers don't do the gross moves that FED pitchers do, and MLB umpires are more strict on a lot of the subtle stuff than we would be at all lower levels.